|Year|Team|Co-Drivers|Car|Class|Laps|Pos.|Class Pos.|
|---|---|---|---|---|---|---|---|
|1972|Ford Motor Company Deutschland|Jochen Mass|Ford Capri 2600RS|S 3.0|152|DNF|DNF|
|1973|BMW Motorsport|Chris Amon|BMW 3.0CSL|T 5.0|160|DNF|DNF|
|1980|BMW Motorsport GmbH|Hans-Georg Bürger  Dominique Lacaud|BMW M1|IMSA|283|15th|5th|
|1981|BASF Cassetten Team GS Sport|Jean-Pierre Jarier  Helmut Henzler|BMW M1|IMSA GTX|57|DNF|DNF|
|1982|BASF Cassetten Team GS Sport|Jean-Louis Schlesser  Dieter Quester|Sauber SHS C6-Ford|C|76|DNF|DNF|
|1985|Rothmans Porsche|Derek Bell|Porsche 962C|C1|367|3rd|3rd|
|1986|Rothmans Porsche|Derek Bell  Al Holbert|Porsche 962C|C1|368|1st|1st|
|1987|Rothmans Porsche AG|Derek Bell  Al Holbert|Porsche 962C|C1|368|1st|1st|
|1988|Porsche AG|Klaus Ludwig  Derek Bell|Porsche 962C|C1|394|2nd|2nd|
|1989|Joest Racing|Bob Wollek|Porsche 962C|C1|382|3rd|3rd|
|1990|Joest Porsche Racing|Derek Bell  Frank Jelinski|Porsche 962C|C1|350|4th|4th|
|1991|Konrad Motorsport|Derek Bell  Frank Jelinski|Porsche 962C|C2|347|7th|7th|
|1993|Le Mans Porsche Team|Walter Röhrl  Hurley Haywood|Porsche 911 Turbo S LM-GT|GT|79|DNF|DNF|
|1994|Le Mans Porsche Team  Joest Racing|Thierry Boutsen  Danny Sullivan|Dauer 962 Le Mans|GT1|343|3rd|2nd|
|1995|Porsche Kremer Racing|Thierry Boutsen  Christophe Bouchut|Kremer K8 Spyder|WSC|289|6th|2nd|
|1996|Porsche AG|Thierry Boutsen  Bob Wollek|Porsche 911 GT1|GT1|353|2nd|1st|
|1997|Porsche AG|Thierry Boutsen  Bob Wollek|Porsche 911 GT1|GT1|238|DNF|DNF|
|1998|Team BMW Motorsport|Steve Soper  Tom Kristensen|BMW V12 LM|LMP1|60|DNF|DNF|

Question: what is the total number of team ?
Answer: 18